Prepare boiling water canner. Heat jars in simmering water until ready to use, do not boil. Wash lids in warm soapy water and set aside with bands.

Process blueberry pulp in a food processor 1 minute or until very smooth. Combine pureed pulp, sugar, and remaining ingredients in a 6qt. stainless steel or enameled dutch oven. Bring to a boil over medium heat, stirring often. Reduce heat, and simmer, stirring constantly, 1 hour or until mixture thickens and holds its shape on a spoon.

Ladle hot butter into a hot jar leaving a 1/4 inch headspace. Remove air bubbles. Wipe jar rim. Center lid on jar and apply band, adjust to fingertip tight. Place jar in boiling-water canner. Repeat until all jars are filled.

Water must cover jars by 1 inch. Adjust heat to medium-high, cover canner, and bring water to a rolling boil. Process half-pint jars 10 minutes, adjusting for altitude. Turn off heat and remove cover. Let jars cool 5 minutes. Remove jars from canner; do not retighten bands if loose. Cool 12-24 hours. Check lids for seal, they should not flex when center is pressed